A Siren is a female program with characteristic white outfit. Their role is often linked to games or competitions.

Sirens equipped contestants for the games in TRON: Uprising, providing them with "battle armor".

In Blackout, a Siren was shown to be able to cast a powerful beam of light from her raised identity disc, strong enough to be as visible from afar as an I/O Tower beam in the ENCOM System. The beam was used ceremonially, to kick off a Light Cycle race, and was apparently not harmful, since the Siren lowered it toward the crowd as the race began.

Lux, a white female program who appears in Identity was also possibly a Siren.

The sirens were first seen when Sam Flynn was deposited in the armory to prepare him for arena combat. Four sarcophagi opened in the walls from which they emerged and proceeded to rid him of his real world garments, before re-clothing him in a full-body black body suit. They then turned to storage compartments, that emerged from the walls of the chamber, to retrieve pieces of armor to further upgrade the young man's suit. Finally, an identity disc was handed from one siren to another and secured to Sam's back. Once they had completed their work, they returned to their sarcophagi.

During the encounter, one of the sirens discreetly noted to another, "He's different," acknowledging Sam's distinction as a user. They otherwise remained largely silent, ignoring Sam's questions as they completed their work. When three of them had returned to their rest positions Gem paused to respond to Sam's final question asking what he should do. "Survive," she replied simply, before she too joined her partners at rest.

The costumes of the sirens were made by spraying balloon rubber over spandex.

Because of the skin-tight material and high heels, it was nearly impossible for the actresses to walk backwards to the holding pods, so to achieve the backwards walk effect, they walked forwards, then the video was reversed in post-production.